1. Field of the Invention
The present invention relates, in general, to a fan motor and a microwave oven equipped with the fan motor and, more particularly, to a fan motor having a simple construction and a microwave oven with the fan motor.
2. Description of the Related Art
A microwave oven is an appliance that heats and/or cooks food placed in its cooking cavity using high-frequency electromagnetic waves generated by the oscillation of a magnetron installed in an electrical device cavity of the microwave oven. That is, during a cooking process, the magnetron installed in the electrical device cavity radiates high-frequency electromagnetic waves, so-called “microwaves,” into the cooking cavity. The microwaves penetrate the food to repeatedly change the molecular arrangement of water laden in the food, thus causing the molecules of water to vibrate and generate frictional heat within the food to cook the food.
The microwave oven is partitioned into the electrical device cavity and the cooking cavity. Several electrical devices, including the magnetron that generates the microwaves, are installed in the electrical device cavity. Food to be cooked is placed in the cooking cavity.
A blowing unit is also installed in the electrical device cavity. The blowing unit removes heat generated by operation of the electrical devices, such as the magnetron, and discharges food odors and smoke generated during the cooking process outside the microwave oven.
Thus, when the blowing unit operates, air is fed into the electrical device cavity to cool the electrical devices in the electrical device cavity. After the air cools the electrical devices, the air passes through the cooking cavity to discharge food odors and smoke generated while cooking to the exterior of the microwave oven.
Generally, the blowing unit includes a fan motor and a blowing fan that is driven by the fan motor. The fan motor has a stator, a rotor that rotates by electromagnetic interaction with the stator, and a rotating shaft that rotates with the rotor to rotate the blowing fan.
The rotating shaft is inserted into the rotor to with the rotor, and extends from both ends of the rotor. The blowing fan is mounted to an end of the rotating shaft. When the blowing fan is rotated by the fan motor, the electrical device cavity is cooled and the cooking cavity is ventilated.
Brackets are mounted to front and rear surfaces of the stator so that both ends of the rotating shaft rotate on a fixed axis when the rotating shaft passing through the rotor rotates with the rotor. Each bracket has a through hole so that the rotating shaft passes through the bracket. Thus, the rotating shaft is rotatably held by the brackets.
The rotating shaft of the conventional fan motor has a length sufficient for the rotating shaft to be held by the brackets, which are mounted to the stator such that one of the brackets is positioned in front of the rotor and the other bracket is positioned in back of the rotor to allow the rotating shaft to rotate on a fixed axis. Thus, the number of components of the fan motor is increased, which increases the manufacturing cost and time, thereby increasing the cost of the microwave oven having the conventional fan motor.